School of Sustainability

A hemp trial in Kutztown puts cover crops before fertiliser

On Rodale Institute's main campus at Kutztown, Pennsylvania, a field is being readied in strips. Some will carry cereal rye through the winter, some a mixture of rye and hairy vetch, and some will lie bare and tilled. Come spring, fibre hemp goes into all of them at two dates, mid-May and early June, and for two seasons researchers will count what emerges, weigh what grows, and test what the fibre is worth at the end.

The questions are unglamorous and that is the point. Rye gives reliable winter cover and smothers weeds, but its residue, mistimed, smothers hemp seedlings too, especially in the cooler, higher ground of the state where the season is short. Vetch fixes nitrogen but is erratic alone in cold, heavy soil. And a few weeks' difference in planting can change how quickly the canopy closes and how the fibre grades at harvest.

The trial builds on several years of hemp work at Rodale, and the finding that frames it is worth sitting with. A study published this year in Crops & Soils reported that no-till plots with cover crops and minimal nitrogen consistently produced stronger, better-quality fibre than conventionally tilled and heavily fertilised ones. The crop, in other words, did better when the field was interfered with less.

Over the two seasons the team will track seedling emergence, height and biomass, weed pressure and leaf nitrogen, alongside soil indicators from microbial activity to water-stable aggregates and infiltration. Results will go out through field days at Kutztown, grower fact sheets and an online seminar, aiming at roughly four hundred Pennsylvania growers. The work is paid for by the state's Specialty Crop Block Grant Program, which tells you hemp is being treated, at last, as a crop rather than a curiosity.

Rodale Institute · Read the source